Accidentally missed Madison County's test last week, so I made sure to try and get out to this one. This siren that I went to is actually one of two Whelens in Limestone County, AL that's within Huntsville's city limits. The other Whelen is a 2910 that was installed just last year.
If you look closely, you may also notice that this siren originally had a fin-back on it. Sadly, Limestone County removed the remaining fins from all of their Whelen Vortexes a few years ago. There is also quite a great echo off of the siren when it faces away from me, which IMO makes this a rather cool recording.
Limestone County, AL tests on the second Monday of the month at 9:15 AM, weather permitting.